This extension implements RFC 2369 for Thunderbird: Special mailing list header fields in the mail are parsed, and the links are displayed in the extended header view. You can click them to simply go to the archive, request help or unsubscribe.

This extensions can import and export mozilla address books at startup and exit of Thunderbird. You can first save a mab at a specific location e.g. on a network or the internet (Version 2.0) and then let it be updated every time TB starts up or...

Based on Dictionary Switcher but more than a thousand times faster and you can choose dictionaries that you want to use. Detects the language of the message that you are composing and changes the spelling dictionary.